Mounting devices of the type to which the present invention relate typically comprise a clamping sleeve located between the bearing and the shaft and a flange located at least on one side of the bearing. A seal is provided between the flange and the housing radially outwardly of the flange and means is provided for displacement of the bearing axially on the sleeve during mounting and dismounting of the bearing so that the width of a slot appearing between the flange and the bearing or a washer associated therewith is altered during axial displacement of the bearing. A device of this general type is shown in Swedish application Ser. No. 450851. In this prior arrangement, the sealing member consists of a sealing lip which is designed to engage the radially outer surface of the flange. However, it has been found that the use of this type of the sealing lip limits the field of use to applications wherein the shaft rotates at a relatively low speed.